16207045721 has 2 divisors, whose sum is σ = 16207045722. Its totient is φ = 16207045720.

The previous prime is 16207045717. The next prime is 16207045739. The reversal of 16207045721 is 12754070261.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15012375625 + 1194670096 = 122525^2 + 34564^2 .

It is a cyclic number.

It is not a de Polignac number, because 16207045721 - 2² = 16207045717 is a prime.

It is not a weakly prime, because it can be changed into another prime (16207045711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8103522860 + 8103522861.

It is an arithmetic number, because the mean of its divisors is an integer number (8103522861).

Almost surely, 2^16207045721 is an apocalyptic number.

It is an amenable number.

16207045721 is a deficient number, since it is larger than the sum of its proper divisors (1).

16207045721 is an equidigital number, since it uses as much as digits as its factorization.

16207045721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23520, while the sum is 35.

The spelling of 16207045721 in words is "sixteen billion, two hundred seven million, forty-five thousand, seven hundred twenty-one".